NBitsTester.scala

NBitsTester.scala

import com.google.common.primitives.{Ints, Longs}
import org.ergoplatform.mining.difficulty.DifficultySerializer

object NBitsTester extends App {
  val nb = 118012349L

  val diff = DifficultySerializer.decodeCompactBits(nb)

  println(nb.toBinaryString)
  println(diff)
  val nb2 = DifficultySerializer.encodeCompactBits(diff / 96)
  println(nb2)
  println(nb2.toBinaryString)

  val diff2 = BigInt.apply(Array[Byte](2, 0, 0, 0))
  println("diff2")
  println(diff2)
  println(DifficultySerializer.encodeCompactBits(diff2).toBinaryString)
  println(DifficultySerializer.encodeCompactBits(diff2 / 128).toBinaryString)
  // 100 00001000 00000000 00000000
  //  11 00010000 00000000 00000000

  val diffb = DifficultySerializer.decodeCompactBits(386197775L)
  println(386197775L.toBinaryString)
  println(DifficultySerializer.encodeCompactBits(diffb / 4).toBinaryString)

  def compare128(nb1: Long, nb2: Long): Boolean = {
    val nBytes1 = Longs.toByteArray(nb1).takeRight(4)
    val nBytes2 = Longs.toByteArray(nb2).takeRight(4)

    println(nBytes1.mkString(","))

    val exp1 = nBytes1.head
    val exp2 = nBytes2.head

    val m1 = Ints.fromByteArray(Array[Byte](0) ++ nBytes1.tail)
    val m2 = Ints.fromByteArray(Array[Byte](0) ++ nBytes2.tail)

    println(exp1)
    println(exp2)
    println(m1)
    println(m2)
    (exp1 == exp2 && m1 < 128 * m2) || ((exp1 - 1 == exp2) && (2 * m1 < m2))
  }

  def nbRecalc(nb: Long, factor: Int) = {
    val diff = DifficultySerializer.decodeCompactBits(nb)
    val diff2 = diff / factor
    DifficultySerializer.encodeCompactBits(diff2)
  }

  println(compare128(nb, nbRecalc(nb, 1)))
}